A current collector system for a vehicle, in particular for a container stacking crane, is known from WO 2010/054852 A2. The known current collector system is fixed to the support leg of the crane and is movable along a trackway on which at least one busbar is arranged. A collector trolley of the current collector system can create an electrical contact with the busbar via a current collector, the collector car being movable for this purpose to an introduction device for the trackway via a telescoping arm movable in the horizontal delivery direction. The collector trolley is supported so as to be freely movable in the vertical delivery direction on a guide of the telescoping arm. Thereby contacts of the current collector can be moved vertically by means of the introduction device up to the busbar in order to create an electrical contact with the busbar.
The freely movable supporting of the collector trolley has the disadvantage that an elaborate introduction device requiring considerable space must be provided for guiding the current collector and the current collector contacts to the busbar.
This will be described for the sake of example with reference to a schematic top view of a container handling center 101 shown in FIG. 1. Such container handling centers 101 are found in ports, principally for transferring containers from ships to freight trucks. Containers are stacked there in a variety of elongated container stacks 102. Travel lanes 103 for freight trucks, which are loaded and unloaded via container stacking cranes, not shown, are located between the container stacks 102. The container stacking cranes move in a travel direction F along the container stacks 102 and extend transversely to the travel direction over a plurality of container stacks 102. The container stacking cranes can also be moved from one block 104 of container stacks 102 to another block 105 of container stacks 106.
Trackways 107, 108 running in the travel direction F with busbars 109, 110 arranged thereon for supplying the container stacking cranes with electrical energy are located alongside the blocks 104, 105, as described in WO 2010/054852 A2, among other places. If a container stacking crane is to shift from block 104 to block 105, its current collector leaves the busbar 109 and drives to the next block 105 with a drive motor powered by fuel or a battery. At block 105, the current collector is then threaded by an introduction device into the busbar 110, from which the container stacking crane is supplied with electrical energy.
An entry zone 111, indicated by a circle in FIG. 1, of the trackway 108 is shown in a top view in FIG. 2. The trackway 108 has a conventional introduction device 112 for the container stacking crane, as is known from WO 2010/054852 A2. First the collector trolley is driven horizontally toward a stop plate 113 and strikes against it. Then the container stacking crane moves in the travel direction F to the busbar 110, the collector trolley, supported to move freely vertically, being brought by means of a first roller arrangement through the upwardly inclined introduction rail 114 to the proper height relative to the busbar 110. Then a second roller arrangement threads the trolley into support rails 115 of the trackway 108, and the current collector is contacted via a current collector introduction device 116 with the busbar 110 so that the container stacking crane is again supplied with electrical energy.
As is easily recognized from FIG. 2, the entry zone 111 requires a relatively large amount of space. Thus the busbar 110 only starts approximately 3.50 m away from the left-hand beginning of the trackway 108 in FIG. 2. Because an introduction device 116 and thus a relatively large entry zone are required at both ends of the trackway 108, considerable stacking space for containers is lost. The container stacking crane must after all be supplied with electrical energy from the busbar in order to lift and move the containers. In principle the entry zone could be made shorter, but that reduces the positioning accuracy of the current collector relative to the busbar in the entry zone, which can frequently lead to expensive and time-consuming damage to the current collector and the busbar.
Another disadvantage is that the container stacking crane must move much more slowly during the entry into the trackway 108 in order to be able to introduce the current collector into the support rails 115 via the introduction device 112 and 116.
Since the entry zone 111 projects far into the driving area designed for trucks, the entry zone 111 must be specially protected against collisions with the trucks.